<!DOCTYPE html>
<html>
<head>
<title>Snap Link Reshaping</title>
<!-- Copyright 1998-2016 by Northwoods Software Corporation. -->
<meta charset="UTF-8">
<script src="go.js"></script>
<script src="SnapLinkReshapingTool.js"></script>
<link href="../assets/css/goSamples.css" rel="stylesheet" type="text/css" />  <!-- you don't need to use this -->
<script src="goSamples.js"></script>  <!-- this is only for the GoJS Samples framework -->
<script id="code">
  function init() {
    if (window.goSamples) goSamples();  // init for these samples -- you don't need to call this
    var $ = go.GraphObject.make;  // for conciseness in defining templates

    myDiagram =
      $(go.Diagram, "myDiagramDiv",  // must name or refer to the DIV HTML element
        {
          // supply a simple narrow grid that manually reshaped link routes will follow
          grid: $(go.Panel, "Grid",
                  { gridCellSize: new go.Size(8, 8) },
                  $(go.Shape, "LineH", { stroke: "lightgray", strokeWidth: 0.5 }),
                  $(go.Shape, "LineV", { stroke: "lightgray", strokeWidth: 0.5 })
                ),
          allowDrop: true,  // must be true to accept drops from the Palette
          "draggingTool.isGridSnapEnabled": true,
          linkReshapingTool: $(SnapLinkReshapingTool),
          // when the user reshapes a Link, change its Link.routing from AvoidsNodes to Orthogonal,
          // so that combined with Link.adjusting == End the link will retain its reshaped mid points
          // even after nodes are moved
          "LinkReshaped": function(e) { e.subject.routing = go.Link.Orthogonal; },
          "animationManager.isEnabled": false,
          "undoManager.isEnabled": true
        });

    // when the document is modified, add a "*" to the title and enable the "Save" button
    myDiagram.addDiagramListener("Modified", function(e) {
      var button = document.getElementById("SaveButton");
      if (button) button.disabled = !myDiagram.isModified;
      var idx = document.title.indexOf("*");
      if (myDiagram.isModified) {
        if (idx < 0) document.title += "*";
      } else {
        if (idx >= 0) document.title = document.title.substr(0, idx);
      }
    });

    // Define a function for creating a "port" that is normally transparent.
    // The "name" is used as the GraphObject.portId, the "spot" is used to control how links connect
    // and where the port is positioned on the node, and the boolean "output" and "input" arguments
    // control whether the user can draw links from or to the port.
    function makePort(name, spot, output, input) {
      // the port is basically just a small transparent square
      return $(go.Shape, "Circle",
               {
                  fill: null,  // not seen, by default; set to a translucent gray by showSmallPorts, defined below
                  stroke: null,
                  desiredSize: new go.Size(7, 7),
                  alignment: spot,  // align the port on the main Shape
                  alignmentFocus: spot,  // just inside the Shape
                  portId: name,  // declare this object to be a "port"
                  fromSpot: spot, toSpot: spot,  // declare where links may connect at this port
                  fromLinkable: output, toLinkable: input,  // declare whether the user may draw links to/from here
                  cursor: "pointer"  // show a different cursor to indicate potential link point
               });
    }

    myDiagram.nodeTemplate =
      $(go.Node, "Spot",
        { locationSpot: go.Spot.Center },
        new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
        { selectable: true },
        { resizable: true, resizeObjectName: "PANEL" },
        // the main object is a Panel that surrounds a TextBlock with a Shape
        $(go.Panel, "Auto",
          { name: "PANEL" },
          new go.Binding("desiredSize", "size", go.Size.parse).makeTwoWay(go.Size.stringify),
          $(go.Shape, "Rectangle",  // default figure
            {
              portId: "", // the default port: if no spot on link data, use closest side
              fromLinkable: true, toLinkable: true, cursor: "pointer",
              fill: "white"  // default color
            },
            new go.Binding("figure"),
            new go.Binding("fill")),
          $(go.TextBlock,
            {
              font: "bold 11pt Helvetica, Arial, sans-serif",
              margin: 8,
              maxSize: new go.Size(160, NaN),
              wrap: go.TextBlock.WrapFit,
              editable: true
            },
            new go.Binding("text").makeTwoWay())
        ),
        // four small named ports, one on each side:
        makePort("T", go.Spot.Top, false, true),
        makePort("L", go.Spot.Left, true, true),
        makePort("R", go.Spot.Right, true, true),
        makePort("B", go.Spot.Bottom, true, false),
        { // handle mouse enter/leave events to show/hide the ports
          mouseEnter: function(e, node) { showSmallPorts(node, true); },
          mouseLeave: function(e, node) { showSmallPorts(node, false); }
        }
      );

    function showSmallPorts(node, show) {
      node.ports.each(function(port) {
        if (port.portId !== "") {  // don't change the default port, which is the big shape
          port.fill = show ? "rgba(0,0,0,.3)" : null;
        }
      });
    }

    myDiagram.linkTemplate =
      $(go.Link,  // the whole link panel
        { relinkableFrom: true, relinkableTo: true, reshapable: true, resegmentable: true },
        {
          routing: go.Link.AvoidsNodes,  // but this is changed to go.Link.Orthgonal when the Link is reshaped
          adjusting: go.Link.End,
          curve: go.Link.JumpOver,
          corner: 5,
          toShortLength: 4
        },
        new go.Binding("points").makeTwoWay(),
        // remember the Link.routing too
        new go.Binding("routing", "routing", go.Binding.parseEnum(go.Link, go.Link.AvoidsNodes))
                      .makeTwoWay(go.Binding.toString),
        $(go.Shape,  // the link path shape
          { isPanelMain: true, strokeWidth: 2 }),
        $(go.Shape,  // the arrowhead
          { toArrow: "Standard", stroke: null })
      );

    load();  // load an initial diagram from some JSON text

    var link = myDiagram.links.first();
    if (link) link.isSelected = true;

    // initialize the Palette that is on the left side of the page
    myPalette =
      $(go.Palette, "myPaletteDiv",  // must name or refer to the DIV HTML element
        {
          maxSelectionCount: 1,
          nodeTemplateMap: myDiagram.nodeTemplateMap,  // share the templates used by myDiagram
          model: new go.GraphLinksModel([  // specify the contents of the Palette
            { text: "Start", figure: "Circle", fill: "green" },
            { text: "Step" },
            { text: "DB", figure: "Database", fill: "lightgray" },
            { text: "???", figure: "Diamond", fill: "lightskyblue" },
            { text: "End", figure: "Circle", fill: "red" },
            { text: "Comment", figure: "RoundedRectangle", fill: "lightyellow" }
          ])
        });
  }


  // Show the diagram's model in JSON format that the user may edit
  function save() {
    saveDiagramProperties();  // do this first, before writing to JSON
    document.getElementById("mySavedModel").value = myDiagram.model.toJson();
    myDiagram.isModified = false;
  }
  function load() {
    myDiagram.model = go.Model.fromJson(document.getElementById("mySavedModel").value);
    loadDiagramProperties();
  }

  function saveDiagramProperties() {
    myDiagram.model.modelData.position = go.Point.stringify(myDiagram.position);
  }
  // Called by "InitialLayoutCompleted" DiagramEvent listener, NOT directly by load()!
  function loadDiagramProperties(e) {
    // set Diagram.initialPosition, not Diagram.position, to handle initialization side-effects
    var pos = myDiagram.model.modelData.position;
    if (pos) myDiagram.initialPosition = go.Point.parse(pos);
  }
</script>
</head>
<body onload="init()">
<div id="sample">
  <div style="width:100%; white-space:nowrap;">
    <span style="display: inline-block; vertical-align: top; padding: 5px; width:100px">
      <div id="myPaletteDiv" style="border: solid 1px gray; height: 620px"></div>
    </span>

    <span style="display: inline-block; vertical-align: top; padding: 5px; width:80%">
      <div id="myDiagramDiv" style="border: solid 1px gray; height: 620px"></div>
    </span>
  </div>
  <p>
    This sample is a simplified version of the <a href="../samples/draggableLink.html">Draggable Link</a> sample.
    Links are not draggable, there are no custom <a>Adornment</a>s, nodes are not rotatable, and links
    do not have text labels.
  </p>
  <p>
    Its purpose is to demonstrate the <a href="SnapLinkReshapingTool.js">SnapLinkReshapingTool</a>,
    an extension of <a>LinkReshapingTool</a> that snaps each dragged reshape handle of selected Links to
    the nearest grid point.
  </p>
  <p>
    Note how the "LinkReshaped" DiagramEvent listener changes the <a>Link.routing</a> of the reshaped Link,
    so that it is no longer AvoidsNodes routing but simple Orthogonal routing.
    This combined with <a>Link.adjusting</a> being End permits the middle points of the link route to be
    retained even after the user moves or resizes nodes.
    Furthermore there is a TwoWay <a>Binding</a> on <a>Link.routing</a>, so that the model remembers
    whether the link route had ever been reshaped manually.
  </p>
  <button id="SaveButton" onclick="save()">Save</button>
  <button onclick="load()">Load</button>
  <textarea id="mySavedModel" style="width:100%;height:300px">
{ "class": "go.GraphLinksModel",
  "linkFromPortIdProperty": "fromPort",
  "linkToPortIdProperty": "toPort",
  "modelData": {"position":"0 0"},
  "nodeDataArray": [ 
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-3, "loc":"184 176"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-2, "loc":"248 248"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-4, "loc":"424 192"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-5, "loc":"320 152"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-6, "loc":"424 320"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-7, "loc":"352 256"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-8, "loc":"176 296"},
{"text":"DB", "figure":"Database", "fill":"lightgray", "key":-9, "loc":"288 344"},
{"text":"Step", "key":-10, "loc":"96 240"},
{"text":"Step", "key":-11, "loc":"536 280"}
 ],
  "linkDataArray": [
{"from":-10, "to":-11, "fromPort":"R", "toPort":"L", "points":[121,240,131,240,132,240,132,240,216,240,216,176,264,176,264,104,392,104,392,240,480,240,480,280,501,280,511,280], "routing":"Orthogonal"}
  ]}
  </textarea>
</div>
</body>
</html>
